This invention relates to a color correction method and apparatus and picture processing method and apparatus used on the site of editing picture material.
On the editing site for picture material, such as a broadcasting station, the color temperature or color tone is adjusted by correcting the signal level of picture signals using a color correction device comprised of a picture processing device.
The color correction device is configured for performing primary processing and secondary processing. The primary processing corrects the signal level of the picture signals, mainly the luminance level, such as white level, black level or gamma correction. The secondary processing corrects the signal level of picture signals, mainly the color vector.
On the editing site, the above processing corrects fluctuations of the color temperature among editing materials recorded on different date and time. Thus, on the editing site, the processing characteristics are set on repeated pre-viewing, as the processing results are checked, so that fluctuations among materials are substantially indiscernible.
The color correction device is of the hardware structure with the use of a gate array or of the software structure by computational processing. On the broadcasting site, an apparatus by the hardware configuration is mainly used.
Meanwhile, in the conventional color correction device, the colors that can be set as processing objects (comprised of the source vector and generally comprised of six colors of red, green, blue, yellow, cyan and magenta) and the number thereof are limited such that fine adjustment of the color hue is correspondingly limited. Moreover, adjustment of characteristics, such as the range or degree for correction, is limited for these source vectors.
Thus, the conventional color correction device has a drawback that processing cannot be executed with high degree of freedom.
As a method for resolving this drawback, it may be contemplated to correct the signal level of the picture signals by the hardware configuration employing a lookup table and to vary the contents of the lookup table by operator setting. That is, if the signal level of the picture signals is corrected by the lookup table, the desired color can be set to the source vector, while the number of source vectors or the range of correction can be set to various values, thus enabling execution of processing to a high degree of freedom.
However, if the processing of high degree of freedom can be executed, it becomes correspondingly difficult for the operator to grasp correctly the degree of processing thus complicating the operation.
It is therefore an object of the present invention to provide a picture processing method and apparatus whereby processing to a high degree of freedom can be executed by a simplified operation.
It is another object of the present invention to provide a color correction method and apparatus whereby color correction can be made on designation of the color hue range.
It is yet another object of the present invention to provide a color correction method and apparatus whereby color correction can be made on designation of plural color hues.
The present invention provides a color correction device for correcting the color of plural pixels making up a source video image including parameter setting means for setting plural parameters for designating the source color and the destination color and computing means for computing correction data for color correction of the source color to the destination color, using plural parameters as set by the parameter setting means, storage means for storing the correction data computed by the computing means, and color correction means for correcting the color of a pixel associated with the source color contained in the source video image to the destination color, using the correction data stored in the storage means.
In the color correction device of the present invention, computation by the computing means is performed by a software program and the processing performed by the color correction means is performed by hardware.
In the color correction device of the present invention, the storage means is a lookup table for storing the pixel color and the correction data in association with each other.
In the color correction device of the present invention, the source color and the destination color are represented by a vector in a color space.
In the color correction device of the present invention, the parameter setting means includes means for setting parameters concerning the color hue angle and the saturation degree as parameters concerning the source color and the destination color, respectively.
In the color correction device of the present invention, the parameter setting means further includes gain setting means for setting the parameters concerning the gain value of the correction data and the computing means computes the correction data using parameters concerning the color hue angle and the saturation degree set by the parameter setting means as parameters for the source color and the destination color and parameters concerning the gain value set by the gain setting means.
In the color correction device of the present invention, the parameter setting means further includes color hue range setting means for setting parameters concerning the color hue range of the source color and, if the color contained in the source video image is within the color hue range as set by the color hue range setting means, the computing means computes the correction data using parameters concerning the color hue angle and the saturation degree set by the parameter setting means as parameters for the source color and the destination color and parameters concerning the gain value set by the gain setting means.
The present invention also provides a color correction device for correcting the colors of plural pixels making up a source video image including parameter setting means for setting plural parameters for prescribing the source color range and the destination color range in a color space, computing means for computing correction data for correcting the color contained in the source color range into the color contained in the destination color range and color correction means for correcting the pixel color to a color corresponding to the destination color range based on the corrected data contained in the source color range if the color of the pixel constituting the source video image is a color contained in the source color range.
In the color correction device of the present invention, the color hue direction of the source color range is defined by a source vector on the color space and the color hue direction of the destination color range is defined by the destination vector on the color space.
In the color correction device of the present invention, the parameter setting means includes means for setting at least parameters concerning the source color hue direction, source color hue range and the source saturation degree, as plural parameters prescribing the source color range and means for setting parameters concerning at least the destination color hue direction and destination saturation degree as plural parameters prescribing the destination color range.
In the color correction device of the present invention, the parameter setting means further includes gain setting means for setting parameters concerning the gain value of the correction data and the computing means computes the correction data using parameters concerning the source color hue direction, source color hue range and source saturation degree as set by the parameter setting means, parameters concerning the destination color hue direction and the destination saturation degree and parameters concerning the gain value as set by the gain setting means.
In the color correction device of the present invention, the gain setting means sets the gain value from one color hue to another so that the closer the color hue angle to be computed to the color hue direction of the color hue range, the larger becomes the gain value, and so that the remoter the color hue angle to be computed from the color hue direction of the color hue range, the smaller becomes the gain value.
In the color correction device of the present invention, the computing means computes the correction data from one color hue to another so that the closer the color hue angle to be computed to the color hue direction of the color hue range, the larger becomes the correction data value, and so that the remoter the color hue angle to be computed from the color hue direction of the color hue range, the smaller becomes the correction data value.
In the color correction device of the present invention, the color correction means converts the pixel color to the color having the color hue angle which is closer to the destination color hue direction the closer the color hue angle of the pixel to the source hue direction, the color correction means converting the pixel color to a color having the color hue angle which is closer to the pixel color hue direction the remoter the color hue angle of the pixel from the source hue direction.
In the color correction device of the present invention, the computing means computes the correction data, selectively using a source algorithm for correcting the color of the pixel corresponding to the source color range to the color corresponding to the destination color range, while maintaining a constant source saturation degree, and also selectively using a destination algorithm for correcting the color of the pixel corresponding to the source color range to the color corresponding to the destination color range, while varying the source saturation degree.
The color correction device of the present invention is comprised of a computer having the parameter setting means and the computing means and a picture processing unit having the color correction means. In the color correction device of the present invention,. the computer is programmed for displaying on a computer monitor a graphical interface comprised of a parameter setting window for interactively setting parameters concerning the source color hue direction, source color hue range, source saturation degree, destination color hue direction and the destination saturation degree, and a view window for displaying a video image prior to color correction by the color correction means and a video image subsequent to color correction.
The present invention also provides a color correction method for correcting the colors of plural pixels making up a source video image including setting a plurality of parameters for prescribing a source color range and a destination color range in a color space, computing correction data for correcting the color contained in the source color range to the color contained in the destination color range, and correcting the color of the pixel to the color corresponding to the destination color range, based on the correction data, if the color of the pixel constituting the source video image is the color contained in the source color range.
In the color correction method of the present invention, at least parameters concerning the source color hue direction, source color hue range and the source saturation degree are set as the plural parameters for prescribing the source color range, and parameters concerning at least the destination color hue direction and the destination saturation degree are set as the plural parameters for prescribing the destination color range.
In the color correction method of the present invention, parameters concerning the gain value of the correction data are set and the correction data are computed using parameters concerning the source color hue direction, source color hue range, source saturation degree, destination color hue direction and the destination saturation degree, and also using parameters concerning the gain.
In the color correction method of the present invention, the gain is set in association with each color hue angle so that the closer the color hue angle to be computed to the color hue direction of the color hue range, the larger becomes the gain value, and so that the remoter the color hue angle to be computed from the color hue direction of the color hue range, the smaller becomes the gain value.
In the color correction method of the present invention, the correction data is computed from one color hue angle to another so that the closer the color hue angle to be computed to the color hue direction of the color hue range, the larger becomes the value of the correction data, and so that the remoter the color hue angle to be computed from the color hue direction of the color hue range, the smaller becomes the value of the correction data.
In the color correction method of the present invention, the closer the color hue angle of the pixel to the color hue direction of the source, the closer to the destination color hue direction is the color hue angle of the color to which is converted the pixel color, and the remoter the color hue angle of the pixel from the source color hue direction, the closer to the pixel color hue angle is the color hue angle of the color to which is converted the pixel color.
In the color correction method of the present invention, the correction data is computed, selectively using a source algorithm for correcting the pixel color corresponding to the source color range to the color corresponding to the destination color range while maintaining the source saturation degree constant and a destination algorithm for correcting the pixel color corresponding to the source color range to the color corresponding to the destination color range while varying the source saturation degree.
The present invention also provides a color correction device for correcting plural pixel colors constituting a source video image, including parameter setting means for setting parameters concerning first to N""th source vectors and first to N""th destination vectors individually associated with the first to N""th source vectors in a color space, computing means for computing comprehensive correction data based on plural correction data from the first correction data for correcting the color represented by the first source vector to the color represented by the first destination vector up to the N""th correction data for correcting the color represented by the N""th source vector to the color represented by the N""th destination vector and color correction means for correcting the color of the pixel to the color of the destination vector associated with the source vector, based on the comprehensive correction data computed by the computing means, if the color of the pixel constituting the source video image is the color on any of the first to N""th source vectors.
In the color correction device of the present invention, the parameter setting means further includes means for setting parameters concerning the first to N""th color hue window for specifying the color hue range of the source vector and parameters concerning the gain values of the first to N""th color hue windows in association with the first to N""th source vectors.
In the color correction device of the present invention, the computing means computes the comprehensive correction data based on the first to N""th source vectors, first to N""th gain values of the first to N""th color hue windows and the first to N""th correction data.
In the color correction device of the present invention, the parameter setting means computes the parameters concerning the gain value from one color hue angle to another so that the closer the color hue angle to be computed to the source vector, the larger is the value of the correction data, and so that the remoter the color hue angle to be computed from the source vector, the smaller is the gain value.
In the color correction device of the present invention, the computing means computes the correction data corresponding to the distance from the source vector so that the closer the color hue angle to be computed to the source vector, the smaller becomes the value of the correction data, and so that the remoter the color hue angle to be computed from the source vector, the smaller becomes the value of the correction data.
In the color correction device of the present invention, the closer the color hue angle of the pixel to the source vector, the closer to the destination vector becomes the color hue angle of the color to which is converted the pixel color, and the remoter the color hue angle of the pixel from the source vector, the closer to the pixel color hue angle is the color hue angle of the color to which is converted the pixel color.
In the color correction device of the present invention, the correction data is computed, selectively using a first algorithm for correcting the pixel color corresponding to the first color range to the color corresponding to the second color range while maintaining the source saturation degree constant and a second algorithm for correcting the pixel color corresponding to the first color range to the color corresponding to the second color range while varying the source saturation degree.
The color correction device of the present invention is comprised of a computer having the parameter setting means and the computing means and a picture processing unit having the color correction means.
In the color correction device of the present invention, the computer is programmed for displaying on a computer monitor a graphical interface comprised of a parameter setting window for interactively setting parameters concerning the color hue range of the source vector and the destination vector and a view window for displaying a video image prior to color correction by the color correction means and a video image subsequent to color correction.
The present invention provides a color correction method for correcting the colors of plural pixels making up a source video image includes setting parameters concerning first to N""th destination vectors individually associated with the first to N""th source vectors, computing comprehensive correction data based on plural correction data from first correction data for correcting the color represented by the first source vector to the color represented by the first destination vector up to the N""th correction data for correcting the color represented by the N""th source vector to the color represented by the N""th destination vector and correcting the pixel color to the color of the destination vector associated with the source vector, based on the comprehensive correction data, if the pixel color making up the source video image is the color on one of the first to N""th source vectors.
The color correction method of the present invention further includes setting parameters concerning the first to N""th color hue window for specifying the color hue range of the source vector and parameters concerning the gain value of the first to N""th correction data in association with the first to N""th source vectors.
The color correction method of the present invention further includes computing the comprehensive correction data based on the first to N""th source vectors, first to N""th destination vectors, first to N""th color hue windows and on parameters concerning the first to N""th correction data.
The color correction method of the present invention further includes setting the parameters concerning the gain value from one color hue angle to another so that the closer the color hue angle to be computed to the source vector, the larger becomes the gain, and so that the remoter the color hue angle to be computed from the source vector, the smaller becomes the gain value.
The color correction method of the present invention further includes computing correction data corresponding to the separation from the source vector so that the closer the color hue angle to be computed to the source vector, the larger becomes the value of each correction data and so that the remoter the color hue angle to be computed from the source vector, the smaller becomes the value of each correction data.
In the color correction method of the present invention, the closer the color hue angle of the pixel to the source vector, the closer to the destination vector is the color hue angle of the color to which is converted the pixel color, and the remoter the color hue angle of the pixel from the source vector, the closer to the pixel color hue angle is the color hue angle of the color to which is converted the pixel color.
In the color correction method of the present invention, the correction data is computed, selectively using a first algorithm for correcting the pixel color corresponding to the first color range to the color corresponding to the second color range while maintaining the source vector constant and a second algorithm for correcting the pixel color corresponding to the first color range to the color corresponding to the second color range while varying the source vector.
The present invention also provides a color correction device for correcting plural pixel colors constituting a source video image including vector designating means for designating plural destination vectors individually associated with the source vectors in a color space, computing means for computing comprehensive correction data for correcting colors on the plural source vectors to the color represented individually associated with the plural source vectors and color correction means for correcting the color of the pixel constituting the source video image to the color of the destination vector associated with the source vector, based on the comprehensive correction data, if the color of the pixel is the color on any of the plural source vectors.
The present invention also provides a color correction method for correcting the colors of plural pixels making up a source video image includes setting parameters concerning first to N""th destination vectors individually associated with the first to N""th source vectors, computing comprehensive correction data based on plural correction data from first correction data for correcting the color represented by the first source vector to the color represented by the first destination vector up to the N""th correction data for correcting the color represented by the N""th source vector to the color represented by the N""th destination vector, and correcting the pixel color to the color of the destination vector associated with the source vector, based on the comprehensive correction data, if the pixel color making up the source video image is the color on one of the first to N""th source vectors.
The color correction method of the present invention further includes setting parameters concerning the first to N""th color hue window for specifying the color hue range of the source vector and parameters concerning the gain value of the first to N""th correction data in association with the first to N""th source vectors.
The color correction method of the present invention further includes computing the comprehensive correction data based on the first to N""th source vectors, first to N""th destination vectors, first to N""th color hue windows and on parameters concerning the first to N""th correction data.
The color correction method of the present invention further includes setting the parameters concerning the gain value from one color hue angle to another so that the closer the color hue angle to be computed to the source vector, the larger becomes the gain, and so that the remoter the color hue angle to be computed from the source vector, the smaller becomes the gain value.
The color correction method of the present invention further includes computing correction data corresponding to the separation from the source vector so that the closer the color hue angle to be computed to the source vector, the larger becomes the value of each correction data and so that the remoter the color hue angle to be computed from the source vector, the smaller becomes the value of each correction data.
In the color correction method of the present invention, the closer the color hue angle of the pixel to the source vector, the closer to the destination vector is the color hue angle of the color to which is converted the pixel color, and so that the remoter the color hue angle of the pixel from the source vector, the closer to the pixel color hue angle is the color hue angle of the color to which is converted the pixel color.
In the color correction method of the present invention, the correction data is computed, selectively using a first algorithm for correcting the pixel color corresponding to the first color range to the color corresponding to the second color range while maintaining the source vector constant and a second algorithm for correcting the pixel color corresponding to the first color range to the color corresponding to the second color range while varying the source vector.
The present invention also provides a color correction device for correcting plural pixel colors constituting a source video image including vector designating means for designating plural destination vectors individually associated with the source vectors in a color space, computing means for computing comprehensive correction data for correcting colors on the plural source vectors to the color represented individually associated with the plural source vectors and color correction means for correcting the color of the pixel constituting the source video image to the color of the destination vector associated with the source vector, based on the comprehensive correction data, if the color of the pixel is the color on any of the plural source vectors.
The present invention also provides a picture processing apparatus including data correcting means having a lookup table and adapted for correcting input data by the lookup table for outputting the corrected data, and table updating means for updating the contents of the lookup table, the lookup table holding data corresponding to chroma signals of picture signals.
In the picture processing apparatus of the present invention, the data correcting means has polar coordinate transforming means for transforming the chroma signals into polar coordinate signals for generating angular data corresponding to the chroma signals referenced to a predetermined reference axis, the lookup table outputting data it holds using the angular data as addresses.
In the picture processing apparatus of the present invention, the polar coordinate transforming means outputs the angular data with a number of bits larger than the chroma signals.
In the picture processing apparatus of the present invention, the lookup table outputs correction data correcting the picture signals, using data of the color hue of the picture signals as addresses, and the data correction means includes polar coordinate transforming means for transforming the chroma signals by polar coordinate transformation for outputting the data of the color hue of the chroma signals to the lookup table, and computational processing means for correcting the chroma signals by the correction data.
In the picture processing apparatus of the present invention, the lookup table outputs correction data correcting the color hue and the saturation degree of the picture signals, using data of the color hue of the picture signals as addresses and the data correction means includes polar coordinate transforming means for transforming the chroma signals by polar coordinate transformation for outputting the data of the color hue of the chroma signals to the lookup table, and computational processing means for correcting the chroma signals by the correction data.
In the picture processing apparatus of the present invention, the lookup table outputs correction data correcting luminance and the color hue of the picture signals, using data of the color hue of the picture signals as addresses and the data correction means includes polar coordinate transforming means for transforming the chroma signals by polar coordinate transformation for outputting the data of the color hue of the chroma signals to the lookup table, and computational processing means for correcting the chroma signals by the correction data.
In the picture processing apparatus of the present invention, the table updating means includes at least input means for inputting the color hue of a processing object and the color hue of a processing target and data generating means for generating data for storage in the lookup table, the data generating means generating the data for storage in the lookup table for correcting the color hue of the processing object in the picture signals to the color hue of the processing target using the color hue of the processing object and the color hue of the processing target as reference.
In the picture processing apparatus of the present invention, the table updating means includes at least input means for inputting the color hue and the saturation degree of a processing object and the color hue and the saturation degree of a processing target and data generating means for generating data for storage in the lookup table, the data generating means generating the data for storage in the lookup table for correcting the color hue and the saturation degree of the processing object in the picture signals to the color hue and the saturation degree of the processing target using the color hue and the saturation degree of the processing object and the color hue and the saturation degree of the processing target as reference.
In the picture processing apparatus of the present invention, the data generating means has at least input means for inputting the range of the processing object and data generating means for generating data for storage in the table updating means and the data generating means weights the correction value by a weighting function maintained at a significant value in a range of the processing object for generating data for storage in the lookup table for correcting the color hue of the processing object to the color hue of the processing target.
In the picture processing apparatus of the present invention, the table updating means includes input means for inputting at least the extent of processing and data generating means for generating data stored in the lookup table and the data generating means weighting the correction value by a preset function to generate data stored in the lookup table to correct the color hue of the processing object to that of the processing target.
In the picture processing apparatus of the present invention, the table updating means includes input means for inputting a plurality of sets of the color hue of the processing object and the color hue of the processing target and data generating means for generating data for storage in the lookup table, the data generating means generating correction data for correcting the color hue of the processing object to the color hue of the processing target for each of the sets of the color hues of the processing object and the processing target, and collecting the correction data of each set to generate data for storage in the lookup table.
The present invention also provides a picture processing apparatus including first data correction means having a first lookup table for correcting input data by the first lookup table for outputting the corrected data, second data correction means having a second lookup table for correcting input data by the second lookup table for outputting the corrected data and table updating means for updating the contents of the first and second lookup tables, the first lookup table holding data corresponding to the luminance level of picture signals and the second lookup table holding data corresponding to the chroma level of picture signals.
The present invention also provides a picture processing apparatus for correcting the color hue of a picture being processed, including color hue correction means for weighting the color hue of each pixel of the picture being processed with a predetermined correction value by a weighting function held at a significant value in a range referenced to a predetermined reference color hue for correcting the color hue of each pixel of the picture being processed to a color hue of a processing object, picture displaying means for displaying a color distribution picture obtained on projecting pixels of the picture being processed, represented in a three-dimensional space, on a uv plane, and updating processing means for changing the condition for correcting the color hue by designation on the color distribution picture.
In the picture processing apparatus of the present invention, the updating processing means displays the correction range by the weighting function on the color distribution picture and changes the correction range by designation on the color distribution picture to change the color hue correction condition to correct the color hue.
In the picture processing apparatus of the present invention, the updating processing means accepts pixel designation on the picture being processed to display a marker at a position in register with the accepted pixel on the color distribution picture.
In the picture processing apparatus of the present invention, the updating processing means displays the reference color hue on the color distribution picture and changes the reference color hue by designation on the color distribution picture to change the color hue correction condition.
In the picture processing apparatus of the present invention, the updating processing means accepts pixel designation on the picture being processed to display a marker at a position on the picture being processed in register with the accepted pixel.
In the picture processing apparatus of the present invention, the updating processing means displays the color hue of a correction target corresponding to the reference color hue on the color distribution picture and changes the color hue of the correction target by designation on the color distribution picture to change the correction amount to change the color hue correcting condition.
In the picture processing apparatus of the present invention, the updating processing means accepts pixel designation on the picture being processed to display a marker at a position on the picture being processed in register with the accepted pixel.
The present invention also provides a picture processing method for correcting the color hue of a picture being processed including weighting the color hue of each pixel of a picture being processed with a predetermined correction value by a weighting function held at a significant value in a range referenced to a predetermined reference color hue for correcting the color hue of each pixel of the picture being processed to a color hue of a processing target, displaying a color distribution picture obtained on projecting pixels of the picture being processed, represented in a three-dimensional space, on a uv plane, and changing the condition for color hue correction by designation on the color distribution picture.
The picture processing method of the present invention further includes displaying the range of correction by the weighting function on the color distribution picture, and changing the correction range by designation on the color distribution picture to change the color hue correcting condition.
The picture processing method of the present invention further includes accepting pixel designation on the picture being processed and displaying a marker on the color distribution picture in register with the accepted pixel.
The picture processing method of the present invention further includes displaying the reference color hue on the color distribution picture and changing the reference color hue by designation on the color distribution picture for changing the color hue correcting condition.
The picture processing method of the present invention further includes accepting pixel designation on the picture being processed and displaying a marker on the color distribution picture in register with the accepted pixel.
The picture processing method of the present invention further includes displaying the color hue of the correction target corresponding to the reference color hue on the color distribution picture and changing the color hue of the correction target by designation on the color distribution picture to change the amount of correction to change the color hue correction condition.
The picture processing method of the present invention further includes accepting pixel designation on the picture being processed and displaying a marker on the color distribution picture in register with the accepted pixel.